I have been a “sidewalk astronomer” for just over a year, however, I have been an astronomer for over ten years and have owned at least one telescope for most of that time. I currently own seven telescopes but that’s a long story I’ll save for another article. My wife and I started doing some formal astronomy programs for the National Park Service in Groveland, CA a few years ago and greatly enjoyed sharing our knowledge of the night sky with others. These programs were great fun and well-appreciated, however, they demanded a lot of work as well as traveling across the state and they only happened a few times a year.

On February 7, 2006, I purchased a Coronado Personal Solar Telescope from Scope City in San Francisco. This is an amazing telescope designed exclusively for viewing solar prominences, solar flares and surface detail of the Sun, all at an amazingly affordable price. That afternoon, I was out on the street testing out the scope and ending up showing five different passersby prominences on the sun. (Prominences are gas eruptions that shoot up for many tens of thousands of miles off the surface of the sun. They can last for anywhere from a few hours to several weeks.)

Each of these people became so excited by what they were seeing, that I, too, got excited - not only about seeing the Sun but about sharing it with others. That night, I took one of my other telescopes, a 5 inch Schmidt-Cassegrain telescope, to the local Blockbuster store a block and a half away and set up the scope outside on the sidewalk on a camera tripod showing the Moon to any one who would take a minute to stop and see.

It was amazing! I showed the Moon to 25 or 30 people in about an hour’s time and every one was excited and energized by the view through the telescope. I was asked many questions about the Moon and about why I was out there showing it to others. I heard comments such as “Wow!” “I can’t believe it!” “It’s so beautiful!” over and over again. The moon is always a beautiful sight but if you have never seen it through a telescope, there’s really no way to imagine how it looks up close and personal through a good telescope.

But the most amazing thing about that night was that I, a life-long introvert, became really outgoing and gregarious with my little telescope by my side. I am normally very shy and reserved around strangers, yet I found myself calling out to people I had never met, “Come see the Moon through a telescope!â€? I must admit that I really surprised myself, yet in retrospect, it was really no surprise. Every time I look through a telescope or talk about the night sky, I get excited and feel like I’m seven years old again, when the world was bursting with promise and surprises. That’s the great thing about Astronomy – every one becomes a kid again!

And so I became a sidewalk astronomer. Several times a month, I go out to Blockbuster around the corner or take the car to other neighborhoods in San Francisco to share the night sky with total strangers (although I have made many friends along the way). A very small minority are unimpressed with the views, but I’d guess 95% of my “customersâ€? are highly satisfied with my community service. I’m asked many questions (not all of which I can answer) and hear many kind words throughout each evening. Once in a while I get someone a little scary or strange, but the vast majority of people are kind, friendly, inquisitive and truly appreciative of my efforts.

There is an astronomer in San Francisco by the name of John Dobson (now over 90 years old) who started the sidewalk astronomy movement many years ago. John’s quest is simple – if 1,000,000 astronomers each showed 6,000 people the Moon or Saturn or Jupiter through a telescope, then every one in the world will get to see these amazing wonders first hand! I had always been inspired by John’s vision but never could envision myself out there on the cold sidewalk talking to strangers until that fateful day last year. Since then, I have shown at least 1,000 people in San Francisco the Moon, the Sun, Saturn, Jupiter and even a few deep sky objects such as the Pleiades and the Orion Nebula. And each day, I find myself watching the weather forecast each day to see if that night might be a good night to take the scope out on the streets again.

I had just come over the crest of a dune when I spotted my one of my favorite birds - the Western Sandpiper. There were a couple of flocks of sandpipers of about a dozen each, following the waves in and out looking for a noon time meal of invertebrates in the wet sand. I am not an avid birder, but I do enjoy knowing what bird I’m observing and learning what I can about its Natural History. The Western Sandpiper is a pretty little shore bird that stands about four inches high, with a white chin and breast and beautiful light brown mottling on its back. When running along the beach, one can see a jet black point on its tail and when it takes off for a short flight, it’s possible to observe its wings of brown with a white strip running down the middle and the back edge trimmed in black. As they feed along the beach chasing the receding waves, their heads bob up and down like little sewing machines.

Occasionally, you’ll hear a little “peep” from the Western Sandpiper, and, in fact, all of the little shorebirds are called Peeps by birders. There are many types of peeps that are quite similar and they can be difficult to differentiate even with binoculars, but my Peterson Guide to Western Birds has a great tip about identifying the Western Sandpiper - they look like little windup toys running along the beach. And that’s how I could identify them so quickly from 50 or 60 yards away. I followed several flocks of Sandpipers along the beach as I worked my way north towards the Park. These birds are not shy and today I was able to get within 6 or 7 feet of a couple of them. The distance that a wild bird will allow a human to approach is called the “flight distance” and these birds have one of the shortest that I have seen. One bird even stood for a minute regarding me carefully - it was really cool to see this beautiful bird up close and still for a minute.

I saw another shore bird from time to time as I walked along the beach, always solitary and a bit larger then the Sandpiper, but I did not bring my field guide with me, so I noted its markings and looked it up in my Sibley Guide to Birds when I got home. I had thought when I saw it that it might be a Dunlin but it turned out to be a Willet. With more birding experience, I would have known that upon sighting it (Willets are almost always solitary and Dunlins are usually in flocks). Hopefully, next time I see the Willet, I’ll remember that little fact, but it just points out the value of the hint I gleaned from the Peterson guide about Sandpipers resembling wind up toys.

I once read a book called the Compleate Birder where I learned about GISS (general impression shape and size). When you’re starting out learning how to identify birds (or anything else in Nature), this is a great tool to use. Alan Hopkins, one of San Francisco’s most experienced birders, advises beginning birders to first just observe the bird without binoculars. Watch it move around and observe it in its habitat before you use the binoculars to look for markings to nail down the identification. This is observing the GISS of the bird and is a great help when identifying birds, especially from a distance. Turkey Vultures are really easy to spot because they have a very large wing span and as they glide along in the sky, they rock from side to side. It’s a very distinctive movement that is easily spotted even at a great distance.

As I walked back through the Park, I spotted a Great Egret perched on a log. It spread its wings at one point and I noticed really feathery plumage similar to the Snowy Egret, however, it was too large to be a Snowy and it had a yellow bill. There’s a simple trick to quickly determine if you’re observing a Snowy Egret or a Great Egret. The Great Egret has a yellow bill and black feet and the Snowy Egret has a black bill and yellow feet and is nicknamed “Golden Slippers”.

Farther along I heard the little aria of the House Finch and the repeated cries of the Red-Shouldered Hawk. A couple of weeks ago, my wife and I were walking in the Park in the rain and we were able to get within 20 feet of a Red-Shouldered Hawk. I was surprised we were able to get so close, but I concluded it was probably a juvenile that hadn’t yet developed the fear of humans. I recall it’s beautiful yellow, sharply-curved beak, the delicate mottling of reddish brown and white on its breast and the beautiful black and white stripes on its tail.

I am really fortunate to live near the Park and the beach and to be able to observe such diverse wildlife on a short walk. The walk along the beach was really relaxing as I listened to the sounds of the surf and enjoyed the reflections of the distant clouds in the wet sand left by the receding waves. As I walked through the park, I enjoyed the scents of the various Eucalyptus trees and the Coast Redwoods and the songs and calls of the various birds. Walking has become my favorite exercise - the rhythm of walking puts me in a great frame of mind and the sights and sounds of Nature make me feel whole and connected with the world.

I saw several tall spikes along the Southeast limb (these were approximately 40,000-50,000 miles high) along with a huge prominence along the Southwest limb that looked like a wall (this prominence was approximately 60,000-80,000 miles high and just as wide). To put the size of these prominences in perspective, our Earth is just under 8,000 miles in diameter, so these prominences were massive. There was only one sunspot visible on the surface but, as always, the view was spectacular and awe-inspiring.

Prominences are gas eruptions that reach out from the surface of the Sun into space. Scientists are almost certain that these eruptions are caused by twisting magnetic fields, although the exact science behind their formation and life history is still to be determined. The Sun is a huge ball of gas with a core that is basically solid (14 times the density of lead) and it rotates faster at the center than at the poles. It takes about 25 days for a point at the equator to make a complete revolution and about 35 days for a point near the poles to make the same revolution. Because the Sun has a very strong magnetic field (as does the Earth), scientists speculate that this variance in the rotation rates twists and mangles the magnetic fields, causing most of the Solar activity we can observe - prominences, sun spots, Solar flares and Coronal Mass Ejections.

With my PST, I can routinely observe prominences, filaments, sun spots, plages and surface granulation. Prominences are gas eruptions viewed along the perimeter of the Sun against the black of space, and so stand out very well with great detail. When the same eruptions are viewed directly above the Solar disc, they are called filaments and look like large cracks in the surface. Prominences live for a couple of hours to a couple of weeks and therefore, it’s usually not possible to see them change shape in a single observing session. But over time, changes can be observed and they come in many different shapes and sizes. I have seen prominences that look like trees, fountains, clouds floating in space, loops, spikes and more. One of the coolest things I’ve seen is a prominence with the upper part broken away from the base floating off into space.

Sun spots in the PST are little black dots, each one about the size of Earth, in other words, tiny pinpoints. Sun spots are cooler areas on the surface and they usually form in pairs which are oppositely charged - one positive and one negative. The sun spots go through an 11 year cycle and right now, we are at Solar Minimum with very few sun spots and relatively low Solar activity. For the next four or five years, Solar activity will be on the rise and I’m really looking forward to following this progress in my PST. I just bought the scope last year and I haven’t had the chance to see the Sun in a really active period. I can also observe plages, which are hot spots that surround sun spots and appear almost like ripples in water. They are much lighter in color than the rest of the surface. Surface granulation is also visible in the PST which is called the “orange peel” effect. Most of the surface of the Sun is boiling in huge convection cells very similar to boiling water except at a much slower rate and on a much greater scale. Solar flares are also visible in the PST but it takes a lot of luck to see these. Unlike prominences, these happen very quickly so you have to be looking at the right time to observe one and I have yet to do so.

I love stargazing at night but the view is usually static, unless a meteor shower is going on or a satellite passes overhead (or through your eyepiece!). The view of the Sun changes on a daily and sometimes hourly basis and so is very dynamic and exciting to watch. If you’d like to see some really spectacular solar imagery, you can visit the website of the Solar and Heliospheric Observatory at http://sohowww.nascom.nasa.gov/. The SOHO is a space telescope like the Hubble telescope except that it’s much farther away from the Earth and it only watches the Sun, along with any comets or planets that happen to be near the Sun. At the SOHO website, you’ll see images taken at different wavelengths which means you can view different aspects of Solar activity.

The Sun is so active because it is powered by nuclear fusion. It is a ball of gas about 865,000 miles in diameter (109 times the diameter of the Earth). It consists mostly of hydrogen gas and at the core, the pressure and the temperature are so great that hydrogen atoms are being fused into helium atoms and as a result of that fusion, light and energy are created. That light and energy power all of life on Earth and the same nuclear fusion powers all of the other stars we see at night. The Sun was formed along with all of the rest of the Solar System (the planets, moons, comets, asteroids) about 4,500 million years ago and will last about another 5,000 million years. Once the Sun fuses all the hydrogen into helium, it will start fusing helium into carbon and will swell into a Red Giant that will eventually vaporize the Earth, possibly even engulfing it.

When stars are more massive than the Sun, they have enough energy to keep fusing fuel after all the hydrogen is gone. If massive enough, stars will fuse helium into heavier elements such as carbon, neon, oxygen and silicon all the way up to iron. But no star can generate enough energy and heat to fuse iron into a heavier element, and so when these really massive stars exhaust all of their fuel and all that remains is an iron core, they will then collapse and explode in a cataclysmic explosion called a supernova. The heat of this supernova will create all of the known elements in the Universe heavier than iron. Scientists theorize that there was a large supernova explosion nearby right before the formation of our Sun and the Solar System. That explains the existence of all the heavier elements that we find on the Earth. This explanation of stellar fusion that I have just outlined is greatly simplified. If you’d like to learn more, you can visit a website explaining nuclear energy at http://snews.bnl.gov/popsci/fusion.html.

The Sun in my PST shows as a red ball. The red color comes from an h-alpha filter that allows me to see the fine detail of the prominences and filaments. The h-alpha filter shows only a very narrow band of light and needs to be manufactured to tolerances much greater than that of a standard telescope mirror or lens. Until a few years ago, an h-alpha filter costs thousands of dollars and was out of the reach of most amateur astronomers. The PST came out a few years ago for a price of $499.00 (it is now $599.00) and made Solar observing affordable for many people such as myself. It is a lot to pay for a dedicated scope, however, I haven’t regretted my purchase a single day. I should point out that white light filters are available for almost any telescope at a much lower cost. White light solar filters show sunspots and some solar granulation as well as limb darkening, which a subtle effect seen near the perimeter. I used a white light solar filter with my Celestron C5 telescope for a while and greatly enjoyed the view. If you have a small refractor, you can also project the image of the sun against a piece of white cardboard to see sun spots. It’s not advised to use the projection method with reflectors because you are greatly magnifying the heat of the Sun and may damage the scope.

I have done some sidewalk astronomy with the PST, but it is more difficult showing the Sun as compared with showing the Moon or Saturn. One problem is that everyone knows you’re not ever supposed to look at the Sun so I often need to explain that it’s perfectly safe and sometimes even put my eye up to the eyepiece to show them it really is safe. Another difficulty is that even at high power, the view of the Sun is quite small and prominences are not really obvious at first glance. It takes some coaching to get most people to see the finer detail. I also take along a large photo of the Sun with various details pointed out, along with a small dot representing the size of the Earth to give viewers a better idea of scale. Once people see the fine detail and understand the scale, they are usually impressed and a few will even get excited. However, it’s no match for Saturn (see my post called Saturn Rising).

There is a saying among amateur astronomers that the best scope is the one you use the most. If that is true, I would have to say that of the seven scopes I own, the PST is the best. It is definitely the most fun!

To see some great images of the Sun, visit SOHO.

In spite of the traffic noise, this is my favorite side of the lake because it is where I get some of my best pond water for my microscope. Under a couple of bushes is a grate with quiet, still water and lots of indirect light, which is the perfect environment for many microscopic organisms. I bring along a little plastic bottle or an old jelly jar along with a pair of scissors to snip off some underwater vegetation and carefully collect assorted twigs and leaves that look promising along with the nasty looking water. Serious microscopists will examine the collection with a hand lens at the collection site, however, I like the element of chance. Besides, the micro-animals visible at the low powers of a hand lens (10-20x) are not what I’m after any way. I like the invisible life that is teeming in these waters - ciliates, algae, diatoms, mastigotes, amoeba and bacteria.

After bringing my catch home, I add a little stale tap water (fresh tap water will kill most of these organisms) and place the jar in a corner of my lab (a pine door on concrete bricks). It’s usually recommended to view your catch right away as some organisms will not live more than 24 hours outside of their native habitat, however, I am easily distracted and often don’t get around to seeing what I’ve caught until a couple of days or even a couple of weeks have gone by. I am never disappointed. A single drop of this water under the microscope at 60x is bursting with life. It often reminds me of cartoons I saw as a kid that showed city traffic from an aerial view with cars, trucks and people rushing in every direction. It’s often too much at first but with a little careful scanning, one can usually find a quiet corner that’s not so hectic and where it’s easier to raise the power to 120x and actually observe some detail.

One of the most common types of unicellular organisms are ciliates, usually oval or spherical in shape and covered in layers of tiny hairs (cilia) that help propel them and ingest food. The famous paramecium is one of the most studied organisms in biology and is often seen in pond water. Paramecium are often just visible to the naked eye, but the view through a microscope is stunning. They look like a large slipper and one can see hundreds of tiny cilia along the borders of this organism as well as large circular areas that appear and disappear. These circular areas are Water Expelling Vesicles (WEVs) that move water in and out of the cell to keep the organism in equilibrium with its environment. One of my favorite lighting techniques is dark field or dark ground lighting. I insert a small cardboard arrow into the filter holder of my microscope to block most of the light coming through the field of view and this lights up most organisms in a really unique way. The analogy is often made of sitting in a dark room with the curtains drawn and viewing dust particles in a shaft of light. Incredible detail can be seen with dark field lighting and the view is comparable to the view through a telescope of a star cluster - beautiful little jewels spread on black velvet. The view through a telescope is more user-friendly in that stars are not moving around looking for a meal or trying to avoid being eaten. However, when I’m at my microscope, I’m always nice and warm and I don’t need to wait for a clear night to observe.

Another common denizen of pond water is the mastigote, or flagellate. Some scientists, both professional and amateur, avoid the term flagellate, however, it is still commonly used by many microscopists (just as protozoa is still in use even though it is scientifically outdated). Protozoa means first animal and when I was in grade school, protists were usually placed in the animal kingdom. However, there are now currently five accepted domains - Bacteria, Protists, Fungi, Animals and Plants and so all of the unicellular organisms fall under the domain Protista. So, too, the flagellates were originally named because of the flagella or whip that protrudes from the front and/or rear that are rotated rapidly to both propel the organism through water and draw in food for sustenance. Some scientists now hold the view that only bacteria have true flagella and the protists with whips should be called Mastigotes and their whips should be called undulipodia rather than flagella. Believe it or not, professional scientists can get really worked up over these differences (one book I read said they “nearly came to blows” over the matter), however, amateur scientists such as myself can take a more relaxed view. Regardless of how you name them, these are amazing creatures and a wonder to behold. Again, the dark field view is usually more rewarding as the undulipodia or flagella are often less then a micron in width. A micron is 1,000th of a millimeter, approximately 0.0005118 inches. The wave length of light is roughly one quarter to one half a micron, so the little whips are just visible under a light microscope. The cell shapes range from spherical to elongated and mastigotes generally much smaller than ciliates, however, they often move slower so are easier to observe . One of my favorites is one that I never identified, but it has two undulipodia protruding at 45 degree angles from the anterior or frontal position, each of them rotating so fast that they form little loops. It always reminds me of a microscopic “cowboy” doing really fancy lasso tricks with a rope. Another great mastigote is Euglena, which often forms green “pond scumâ€? in early Spring. This is an oblong shaped organism with one long undulipodia at sticking straight out propelling it through the water while the body morphs into incredible shapes. I saw one recently going through amazing morphs, at one time even turning itself into a mushroom shape

Another common pond water organism is the amoeba. Many amoebas build little shells, also called tests, and so don’t look like the typical blob that you think of when you think of an amoeba. But there are plenty of “blob-type” amoebas in any kind of pond water. The trick to viewing them is lots of patience. They move so slowly that you usually have to watch for several minutes before seeing them morph from one shape to another. These amazing creatures create pseudopods, or feet, at will, to walk around the microscope slide, looking for their next meal. I mentioned above how I really love the dark field view through a microscope, but using dark field, it’s almost impossible to spot these types of amoebas. There is another lighting trick called “oblique lighting” and to use this I pivot my little arrow to block only part of the light coming through the microscope. This creates a 3-D effect that makes it much easier to spot these elusive creatures, but it still requires a patient eye to find them. Once you’ve spotted them, there is no doubt that what you’re seeing is alive and moving and really amazing. No head, no brain, no arms, no legs - just feet and protoplasm and totally bizarre. I mentioned the shelled amoebas above. Many of these are in a group called “Heliozoa” which means sun animals. They are called Sun animalcules because they are little spheres with numerous “spikes” protruding from the shell in every direction making them look like little “suns” with rays sticking out. These are very easy to spot with either dark field or oblique lighting, however, more often than not, there is no movement detectable no matter how long I look. The spikes are actually incredibly tiny poison “needles” that pierce their prey. After an unsuspecting protist is impaled on a spike, the needle turns into a straw to suck the essence out of the prey and feed the amoeba. Pretty weird!

And then there are the diatoms. These are little protists that usually look like little submarines tooling around the slide. They use silicate to create a glass-like shell. The White Cliffs of Dover consist of countless millions of diatom shells. They best time to see these little guys moving around is within 24 to 48 hours of collecting them. They move quite slowly but the movement is enough to easily spot and because of the slow movement, they are quite easy to observe. Diatoms look great under both dark field and oblique lighting.

This is just a very rough overview of the major groups of protists seen in pond water under a microscope. I have a few photos posted on my web site at http://virtualcolony.com/micro/ which show some of the organisms I’ve mentioned and a few that I haven’t. In a later post, I will describe some of the micro-animals commonly found in pond water such as rotifers, nematodes, gastrotrichs and tardigrades, also called water bears.

The views through a telescope of Saturn, the Moon and the bright deep sky objects are always beautiful and amazing, but the views of pond water life through a microscope are equally stunning and fascinating. I’ve thought many times that the people who create special effects for films would be greatly inspired by what I see under the microscope because many pond water organisms are way more bizarre then a giant bug or some green guy with scales and tentacles.

But the most amazing thing about my little drop of pond water from Stow Lake is when I think about the fact that I’m looking at hundreds of organisms in one little corner of one little drop that came from a lake with hundreds of thousands of gallons of water. When I think of all the lakes in Golden Gate Park alone, never mind the rest of the world, the amount of life that is there is staggering. The numbers are so great that it is somewhat like Quantum Mechanics – if you think you understand it, then you really don’t get it.

To see some great photography of protozoa, visit Droplet.

I had just finished setting up and had Saturn in view at about 100x when a couple walked up wearing motorcycle helmets. They announced that it was her birthday and so after a Happy Birthday wish, I invited them to look through the scope. As almost always happens, they were thrilled and delighted with the view of this amazing planet through the scope. Saturn is currently over 760 million miles away and the light takes over an hour to get here, so the view at 100 power is quite small but the rewards are huge. It’s always great to see a nice Hubble image of the ringed planet, or images taken by probes visiting the planet. These photos are crystal-clear and show fantastic detail and there’s no denying their appeal. However, to me and to many of my visitors out on the sidewalk, the live view is unparalleled. There are no tricks or enhancements - just Saturn it its unadorned, natural beauty and looking totally unreal.

I don’t count the actual number of visitors I have when doing sidewalk astronomy, but I would guess I showed somewhere between 60 and 80 people the ringed planet last night. Of these, I can recall maybe five who took a quick look and said “That’s nice” or something to that effect. All of the rest gave comments like “Wow!”, “Oh my God!”, “No, that can’t be real!”, etc. And it’s not what they say, but how they say it, with wonder and delight, that makes the cold night on the sidewalk more than worthwhile. To see people light up with enthusiasm and excitement is a great gift to me - and it’s because I’m giving a great gift to them. It’s just 30 seconds or so at the eyepiece, but for many of my “customers” it changes their whole evening. One pretty young lady said that I “made her night”. For a shy, middle-aged introvert like myself, that’s really nice to hear! (I hear that comment almost every time I go out with the scope). Another young girl gave me a high five and thanked me profusely for taking the time to set up. But the happy, young ladies are just the icing on the cake. Last night, my visitors ranged from aged three to over 70, and every happy face and heart-felt “Thank you” is a very special reward for my efforts – and with each happy response or comment, I always light up like a Christmas Tree.

Before embarking on my sidewalk astronomy efforts, I had done almost no volunteer work outside of a couple of astronomy programs for the National Park Service in the Sierra and one program for the Marin County Open Space District. Now, whenever I’m on the sidewalk with my scope, I feel like I’ve “found my calling”. I’m always a little nervous when I’m on my way to the spot or setting up, but once people start looking and sharing their excitement, the doubts disappear.

I’m sharing one of my great passions - one of mankind’s greatest passions - with total strangers and making friends and spreading joy and happiness pretty much non-stop for an hour or so. What a fantastic way to spend an evening! It really is better to give than receive, especially when the giving is giving of yourself, your time, your knowledge, your love of the beauty of the natural world, your passion. I’m out there doing nothing less than connecting people with the Universe - I can’t think of a better way to spend my time.

To learn more about Saturn, visit Wikipedia.